Method of and apparatus for feeding glass



VIVUU nel. 1;'"1'936,

A. H. STEWART METHOD OF AND APPARATUS FOR FEEDING GLASS Filed liar-Ch 5, 1935 INVENTOR j tional forces.

Patented Dec. l, 1936 UNITED STATES PATENT oFFIcE m01) 0F AND APPARATUS FOB FEEDING GLASS anneau una s. 193s. serai No. 9,440

l2 Claims.

1 Another object of my invention is to control glass flow through an orifice and effect neeking of the mold charges` only by variation of suc- Btill another object of my invention is to pro- 1 vide means for the circulation of molten glass of mold charges which are of uniform temperao ture throughout. v A further object of my invention is to effect better control of glass gob formation at hotter temperatures, by means operable to effect restriction of gravity iiow, in varying degrees throughout the cycle of each gob-forming operation, to thereby more effectively control the shap and sizes of the gobs, notwithstanding changes in temperature of the glass.

One form which my invention may Ytake is ,0 shown in the accompanying drawing wherein Figure l ls a longitudinal sectional view through a portion of a glass furnace and the feeding apparatus; Fig. 2 is a plan view thereof; Fig. 3 is a view diagrammatically representing a portion of Fig. l. on a reduced scale, but at a different stage in the feeding cycle; and'FigA is a similar view showing parts at another stage of the feeding I v40 the numeral I, and the boot or forehearth thereof is represented by theV numeral lp-The boot ll provided with an opening l in its bottom that .serves as an orifice. and an orifice ring or bushlng is detachably connected to the boot. so that 43 the bushings can be readily changed in cases of repairs or replacements, with rings of dierent diameters.

A dome II of clay or other suitable refractory material is placed above the orifice and seats so within a recess formed ln the bottom of the boot so that it will be held against shifting. The dome b provided with a series of openings ll. through which glass may how from the pool into the dome.

and thence and its way through the orifice I.

It lhel dome has an opening i2 in its upper side 'ist ' sure.

through which glass is drawn vat variable rates in an upward direction, in connection with control of feeding movements of the glass. and to effect circulation of the glass in the vicinity of the orifice. A vent i2a is provided. to prevent the en- 5 trapment of air beneath the dome.

An outer bell I3 is periodically raised from and lowered onto the dome by means of a lever Il which has a cam roller l5 that is engaged by a cam i5. A suction line I1 has connection with 10 the bell i3, and is controlled by a valve Il so as to periodically create sub-atmospheric conditions -of variable intensity within the bell. The suct tional or vacuum force is shown as created by a A Venturi device Il, air pressure being supplied through a pipe 2l from a suitable source of pres- An ordinary vacuum pump can be substituted for the venturi, if desired.

At certain stages in the feeding cycle. it will be desired to create a condition of atmospheric pressure within the bell l2. This condition is elfected by closure of the valve I5 and opening of a valve 2l. which will admit atmospheric air to the interior of the bell, through a pipe 22. The

valves il and 2| are actuated by cams 23 and 2l, 25 t respectively. that in turn have drivingcornre-ctiorr-rA with the cam I5, or in any event, they will be driven in timed relation to the raising and lowering movements of the bell i3, as will be hereinalter explained. l 3g A bell is positioned within the bell I2, and has a stern 25 by which the bell may be raised and lowered. the stem 25 passing through a stuiflng box 2l' that prevents leakage of air into the bell I3. Suction is created within the bell 25 35,

through a pipe 25 that is controlled by a valve 29 which is actuated by a cam lll.v Ihe bell 25 is raised and lowered by means of a lever 2i that is oscillated by a cam 22. The cams l5 and 32 are mounted on suitable shafts. A sprocket wheel 0 22 drives one of the shafts. land there is a sprocket chain connection Il between the shafts so that the first-named shaft will drive the other shaft.

It is also possible to change the speed of raising and lowering the bell 25 independently of the 45 bell l2. and vice versa. by suitable cam changes, but in no case is either bell lifted from its seat before the other bell is seated.

The cams l5, 23. 24. 3l and 22 may ordinarily be driven from a single source of power. and will be operated in timed relation to shears li that are employedfor severing charges of glass below the orifice. A

The pool of glass will ordinarily be at approximately the level shown in the drawing, and u will iiow into the dome I l through the openings Il. suming that glass isilowing through the orifice l, the bells Il and 25 are caused to occupy the positions shown in Pig. 3, at which time a sharp suctional force is created within the bell I3, through opening o! the valve Il and closing of the valve 2l. Thereupon, the glass will be drawn up sharply. such upward movement being 4transmitted somewhat to the glass that is susin addition to drawing glass back slightly at the lower side of the orifice, will draw the glass into the domethrough the openings Il. and upwardly through the opening I2 into the bell Il. as shown In Pig. 3. The suctional force is sharply applied for a brief period, so that the inertia to tiow of the glass through the openings II will result in the required suctionalimpulse in the orifice l. which can be of sufficient force to pull the shear stub back into the orifice.

Just at the completion of the necking and shearing-operation, the bell 25 will be lowered to its seat. and the valve Il will be closed and the valves 2| and 29 openedsuiicient suction being provided in the bell 25 to cause some upward ilow of glass through the opening I2, and at the same time. the bell I3 is raised by its cam I3 -to the position shown in Fig. 4. v

By the operation of the valve 2! suflicient suction is maintained in the bell 25 to keep a small quantity of glass flowing upwardly through the opening I2 until the other portion of the glass above the dome is'discharged beneath the lower edge of the raised bell I3. `as shown in Fig. 4. During this time glass flows through the orifice 2 to form a gob. When the bell I3 has been un loaded or freed of its glass. it is again lowered' to its seat and suction applied just before the bell 25 raised. so that another suctional impulse can be imparted to the glass which meanwhile has moved downwardly through the oriiice l.

' be formed than in those cases where propulsive forces are applied to form suspended masses of glass below an orince.

- Another advantage ot the structure arises from the tact that there is circulation of a major portion of the glass through the openings II. upwardly through the opening I2. and down the upper sloping side oi the dome.

There is thus such circulation of the glass as will securevintermlngling of hotter and cooler portions thereof. thus making for better shaped mold charges. and reducing danger of streaks or unevennes In the ware that is produced from the mold charges.

This arrangement for securing circulation of glass by variations in suctional forces is superior to mechanical stirring devices thaLtcn'd to create bubbles in the glass; and eau/se impurities to be stirred into the glassbeng led.

' cf a dome positioned It will be understood that the suction applied to either bell may be sumcient only to retard now through the orince instead of eilecting actual reverse now therein. Also. i! a quick suc tional force Is created In the outer bell. there will be greater retraction at the orince than in the case ol a slower application of suctional force. A prolonged force will, of course. cause greater quantities o! glass to be drawn upwardly through the dome. Unloading of the outer bell. as shown in Fig. 4. can be eilected more quickly i! air pressure instead of atmospheric pressure Is admitted through the pipe 2 2; for fast operations, I may employ super-atmospheric pressure at that point.

While I may at times so arrange the vacuum cycles within the bells to hold the glass stationary in the opening I2 at certain stages of the4 cycle. I prefer to cause the glass to move upwardly through the opening I2 at all times. and arrange the intensities otthe suctional forces to accomplish this. so that I have at all times in some measure restricted gravity action on the glass issuing through the oriiice l.

I claim as my invention:-

1. The method which comprises causing a now o! molten glass from a pool to a' zone above an orifice, allowing a portion o! the stream to now through the oriiice, withdrawing a portion of the glass upwardly from said zone and discharging it laterally into said pool.

2. The method which comprises causing a no' oi' molten glass from a pool to a zone above an orifice. allowing a portion of the stream to now through the orifice, withdrawing a portion of lthe glass upwardly from said zone and discharging it laterally into said pool, the withdrawal force being periodically applied by variations in suction which are sumcient also to periodically retard dow through the orifice.

3. The method of feeding molten glass. which comprises causing glass to Iiow from a pool. through an orifice. under. restricted gravity now. into the form of a mass below the orifice. appLying to the glass above the orifice suctional impulses of varying degree suiliclent to raise the glass above the pool level and to neck the said mass. shearing the glass In a plane adjacent to the oriiice, and causing that portion ot the glass above the pool level to i'iow laterally into the POOL 4. The method of feeding molten glass. which comprises causing glass to flow from a pool past an oriiice below the pool. permitting a portion o! the glass to flow through the prince and form a mass below the orifice. directing another portion of the glass upwardly and laterally into the main body of the pool. and severing the said mass below the orifice.

5. 'Die combination'with a receptacle for a pool of molten glass, having an or'irlce in its lower side. of means providing a restricted zone above said orifice, into which glass may flow from the saldpool. means for creating suction on the surface of the glass in said pool to create upward movement of a portion of the glasst varying rates and to retard discharge through the orifice. and means effective twen reduction oi' the xuctional force. for directig the upwardly drawn glass into the pool exteriorly oi' said zone.

f "6. The combination with a receptacle for a pool of molten glass. having an orifice in its lower side. above the orifice and having restricted communication with said pool and also having an opening in its upper portion. a bell above said opening. a second bell disposed circumferentially of the tirst-named bell. means In: rertically moving said bells alternately, into and out of engagement "ith the dome. and means for eilecting variable pneumatic impulses Iithin the bella.

1. The combination with a receptacle for a pool o! molten glass. haring an orifice in its lower side. o! a bell positioned above said orince. a second bell surrounding the mst-named bell. means for alternately reciprocating said belLs in timed relation to each other. and means operative in timed relation to said movements tot creating variable pneumatic impulses within the bells. Y

l. The combination rith a receptacle tor a pod o! molten glass. hating an orifice in its lower side. of a bell positioned above said orince. a second bei! surrounding the first-named bell. seating surfaces tor said bells, means for vertically moving said belts into and out oi engagement "ith their aeata. and means operative in timed relation to nid movements (or creating pneumatic impulses within the bells.

. 9. 'Die combination with a receptacle for a pool I 0( molten glass having an orice in its lower side. o! a bell positioned above said orifice. means for periodically reciprocating said bell. a second bell surrounding the nrst-named bell. means independent of the mst-named means for periodically reciprocating the second bell. and means operable in timed relation to the reciprocatory movements o! the bells for creating pneumatic impulses therein.

10. The method which comprises causing a no' oi molten glass through an orlncc at the bottom oi a pool. constantly maintaining suc tional impulses on the glass above the orifice to withdraw a quantity of glass therefrom. dlscharging the glass so withdrawn back into said pool. and periodically varying the degree of suctional impulse to vary the quantity withdrawn from tbe orince and thereby oppose gravity 110W to a desired degree.

l1. The method of feeding molten glass. which consists in establishing a flow ot glass from a pool to a submerged orifice, regulating the nov through the orifice by constantly applying suction impulses of varying intensity to the sux'- iace oi the glass over the orilice to continuously "ithdraw varying quantities oi the glass therefrom. and discharging such withdrawn glass back into said pool.

1l The method of feeding molten glass. which consists in establishing a flow of molten glass from a parent body to a pool and from the pool through an orifice. creating a second flow from said pool to retard the now through the orifice and periodically increasing the quantity o! the second tlow from the pool to further retard the now from the pool through the orince.

aimnrzw rt STEWART. 

